In an effort to increase channel capacity, mobile phone carriers have deployed speech coders, such as Advanced MultiBand Excitation (AMBE) coding, in the network to reduce the bit rate of each call. One undesired consequence of employing such speech coders is that the voice quality can be much worse as compared to higher bit-rate speech coders. In particular, AMBE speech coding has shown to produce a spectral imbalance overemphasizing high frequency spectral content. This imbalance produces a “thinness” of the lower frequency speech content and excessive high-frequency sibilance sounds. The network contains Voice Quality Enhancement equipment which can improve these effects, but unfortunately, the telephone networks do not employ any type of signaling to indicate the form of speech coding employed.